Best way to clean grungy oven?

Put a bowl of amonia in the oven let it sit over nite. Take the metal shelves put in large plastic bag.Pour amonia in and tie it with garbage bag tie.The garbage bag needs to lay flat so that the amonia can work its magic on the racks. Next morning wipe oven down.If some of the spots don't come off easy. Use steel wool to scrape off.If you don't have steel wool take a piece of tin foil squeeze it in your hand and that will scrub it off.Do the metal racks the same.Hopw this helps

You could sprinkle some baking soda in the oven and then spritz it with vinegar. Let it set for at least a half hour. Then wipe clean with damp towel. Repeat if necessary. Magic eraser will help with stubborn stains.

When I do client's for inspections, I use oven cleaner on a warm oven, wear a mask, close and let sit for awhile, then I use a large car sponge to wipe clean, and a brillo pad on stubborn bits. If its really horrid, I then put a bowl of vinegar and water in the oven turn on low for an hour. Turn off let sit for a few hours, and then go over with brillo pad again to get the burnt on grease spots off. Wear kitchen rubber gloves to save hands. Buy it all at the Dollar Tree. If there is a deep layer of burnt on charcole on bottom, I use a paint scraper.

Baking soda and vinegar is a good home remedy mixture to attack those hard to remove spots. A steel wool pad will also definitely help